I know Ford calls for 87 octane for my car, but I always use 93. My question is since I do not use a tuner, does 93 provide more hp than 87 octane?

 

As a matter of fact, 91+ Octane is the recommended fuel for this vehicle. The car will only make 412/390 on premium gas. If you use 87/89 you actually will be putting out 402/377.

This info can be found on the official specifications on the Ford website, here.

 

yep...93 to 91 wont make a difference but 91 over 87 will. Depending on who you talk to, some notice a difference and some dont.

 

I don't know if it was due the the new car break in period or what, but I was using 87 octane I had experienced horrible gas mileage until I switched to 91 and above. I was getting around 13 avg in town. I'm up closer to around 16 in town with 91 octane, which is till horrible but closer to the window sticker EPA 17-26

 

Thank you!

 

No problem!

 

The 5.0 picks up some minor power with higher octane on the stock tune. But you'd see larger gains with a custom 87 octane tune compared to the stock tune on 93.

 

Mine has only seen 89 ONCE!!! And that was like 5 gallons. 93 all the way. It's still cheaper than Diesel, (which pisses me off.) Diesel should be MUCH cheaper than it is.

 

^^What he said. The stock tune tables do have different settings according to octane count, 91octane being the max possible tune advances in the tables.
And when you put in a lower octane fuel, the engine's PCM switches to more retarded tables (not retarded as in stupid, but as in retarded spark, cam phasing, etc, LOL)

^^ Again, what he said. A custom tune can unlock more power that the stock tune cannot because it is hobbled for many reasons, primarily a very generous engineer's safety factor, for fuel economy purposes, driveability issues, etc.

 

this is one of life's great mysteries.....